Read - and inking units for a register trier pen as well as ink reservoir or - ink in this case for

摘要

1304656 Polyvinyl pyrrolidone ink composition BECKMAN INSTRUMENTS Inc 15 June 1971 [29 June 1970] 27922/71 Heading C3P [Also in Divisions B6 and C4] An ink for a low pressure automatic writing system comprises a major amount of water and a minor amount of a water-soluble lower alkyl ether of ethylene or diethylene glycol, a watersoluble colorant, and a water-soluble polyvinyl pyrrolidone or polyethylene oxide. The glycol ether is preferably 10-40% by wt. of the ink, and either 0À1-5% polyvinyl pyrrolidone or 0À01-0À3% polyethylene oxide is used. The pH of the ink should be at least 6, and an alkanolamine may be added to increase it to at least 7. A microbiocide, e.g. phenol, may be present in an amount 0À01-0À5% of the ink. The preferred viscosity of the ink is 1-30 cps at 20‹ C. Example 1 and Example 2A-F include polyvinyl pyrrolidone and Examples 3-7 polyethylene oxide.